An optoelectronic semiconductor chip is a layer sequence, produced in a semiconductor process, on a substrate. A semiconductor, by way of example a III-V semiconductor, is provided in the process. Epitaxy layers that have grown on a substrate are possible as a semiconductor layer sequence. The substrate includes by way of example materials such as SiC, sapphire, Ge, Si, GaAs, GaN or GaP. The epitaxy layers comprise by way of example quaternary semiconductors, such as AlInGaN for a blue or green emission spectrum in the visible range, or AlInGaP for a green to red emission spectrum in the visible range. The semiconductors may likewise comprise emission spectra in the non-visible range, by way of example in the UV range. The epitaxy layer can comprise quinternary semiconductors. A semiconductor of this kind is by way of example AlGaInAsP which can be used for the emission of radiation in the infrared range.
The semiconductor layer sequence includes a suitable active zone for the production of electromagnetic radiation. The active zone can include a double heterostructure or a quantum well structure such as a single quantum well (SQW) or a multi quantum well (MQW) for the production of radiation.
An optimally homogenous current density in the active zone, by way of example at the pn junction, is desirable in a light-emitting diode (LED) for high efficiency (i.e. for a large ratio or emitted electromagnetic radiation to supplied power), for a long life and for homogeneous radiation. One problem in this connection is in particular a power supply from the side at which the light is out-coupled (radiation out-coupling side). A current injection on the radiation out-coupling side conventionally occurs by way of contact webs which are applied to the semiconductor. The electrical properties of an LED can be optimized by way of a dense network of contact webs. The webs are disadvantageous for the optical behavior of such a component, however, since they lead to shading and absorption. Since light covers relatively long distances in a thin film LED before it is out-coupled, light may be absorbed at the contact webs. The efficiency of the LED is reduced.
A further problem arises in that a drop in voltage occurs owing to the finite conductivity inside a contact web. A remaining forward voltage over the active zone varies over the chip surface as a result.